Crystal Blue Copper Sulfate Granular Algaecide — 5 lb Aquatic‑Grade, Fast‑Acting Pond Algae Control

Crystal Blue Copper Sulfate Granular is a 5 lb aquatic‑grade algaecide formulated to control filamentous and floating algae in large bodies of water when applied according to label directions.

For pond managers and landowners facing recurring algae blooms, this high‑purity copper sulfate provides a targeted, fast‑acting option. Each bag contains 99% copper sulfate pentahydrate in a granular form designed for broadcast application over dense algal mats. It is intended for sizable water bodies and should not be used in small decorative ponds, pools, or water features or in waters containing copper‑sensitive species.

How quickly will this product reduce visible algae?

Visible thinning of filamentous and floating mats often appears within 24–72 hours after application, depending on water temperature, algae thickness, and circulation. Warmer water (above 60°F) speeds activity, while cooler conditions slow the reaction.

• Works fastest in water temperatures above 60°F.
• Most effective when applied directly on top of dense floating mats.
• Expect visible results within one to three days in favorable conditions.

What precautions should I take when treating a pond?

Use only in large bodies of water as directed and avoid application where sensitive fish species are present. Treat small areas at a time to prevent sudden oxygen depletion caused by rapid die‑off of vegetation, which can harm aquatic life.

• Do not use in waters that contain koi, goldfish, trout, or grass carp.
• Treat limited areas per application to avoid mass die‑off and oxygen drops.
• Follow local regulations and label instructions for safe handling and disposal.

How should I apply the granular copper sulfate for best effect?

Broadcast the granules directly onto thick floating mats or along shorelines where algae accumulates. Measure dose according to algae density and water volume, and avoid dispersing excessively into open water where it will dilute before contacting algae.

• Cast granules onto the top of dense algal mats for concentrated contact.
• Apply in sections rather than the entire pond at once.
• Wear appropriate PPE and avoid contact with skin and eyes during handling.

Will this harm other aquatic plants or wildlife?

Copper sulfate targets algae but can affect other aquatic organisms at certain concentrations. Careful dosing and selective spot treatment reduce non‑target impacts; always check for the presence of sensitive fish and avoid treating areas used for livestock watering or irrigation without guidance.

• Use only in waters without copper‑sensitive species present.
• Avoid treating whole systems at once to protect oxygen levels for fish and invertebrates.
• Consult local authorities if you plan to use treated water for irrigation or livestock.

Who this product is for: Crystal Blue Copper Sulfate Granular, 5 lb, is designed for pond managers, agricultural landowners, and municipal maintenance crews needing a concentrated, aquatic‑grade algaecide for sizable waters. It is suited to users who understand aquatic chemistry, follow label directions, and can restrict use where sensitive species are present. Not recommended for small decorative ponds, pools, or ponds stocked with koi, goldfish, trout, or grass carp.